Lead intoxication is a problem of epidemic proportion in selected areas of big cities, including that around the Bronx Municipal Hospital Center. Despite increased awareness, and mass screening programs, no systematic study regarding the immediate and late consequences of lea@ intoxication if being conducted. The present research project combines animal experiments and clinical observation in order to determine the effect of lead intoxication on kidney function and structure. Micropuncture methods, standard clearance techniques and light and electronmicroscopy will used for this purpose. Newborn and adult rats will be fed diets with low and high lead content and total kidney GFR, renal blood flow, single nephron GFR fractional and intrinsic tubular reabsorptive capacity of sodium, will be determined. Measurements GFR, renal blood flow, franctional sodium and phosphate reabsorption, amino acid clearance, bicarbonate and glucose titrations will be performed on children having serum lead levels above 40 micron gm percent. Kidney tissue will be obtained both from animals and patients and examined by light and electronmicroscopy.